The present invention relates generally to mechanisms for interconnecting electrical leads and electrical medical devices, and more particularly to interconnecting implantable electrical leads and implantable medical electrical devices such as pacemakers, nerve stimulators, implantable defibrillators, implantable monitors and so forth.
As implantable electrical devices have increased in their complexity, there has been an increasing variety of electrical lead systems developed for use in conjunction with these devices. Nowhere is this more apparent than in the context of implantable cardioverter/defibrillators, which may include three, four, five, or more electrodes located on various numbers of implantable electrical leads. The leads themselves may carry one, two, three, or more electrodes, and may employ a variety of different electrical connector configurations and types. As a result, manufacturers of implantable cardioverter/defibrillators have had to produce their products with a variety of connector block configurations, capable of use with different lead systems. For example, Medtronic, Inc. presently manufactures implantable cardioverter/defibrillators with four basic connector designs, designated configurations "B", "C", "D", and "E". The "B" configuration includes three 6.5 mm connector bores for receiving high voltage electrical lead connectors of the type used to couple to cardioversion/defibrillation electrodes and one IS-1 compatible 3.2 mm in-line electrical connector bore for receiving an IS-1 electrical lead connector of the type generally used to couple to cardiac pacing and sensing electrodes. The "C" configuration includes a single 3.2 mm "DF-1" connector bore for receiving high voltage electrical lead connectors used to couple to cardioversion/defibrillation electrodes and a single IS-1 connector bore. The "D" configuration includes three DF-1 connector bores and one IS-1 connector bore. The "E" configuration includes two 6.5 mm connector bores and two 5 mm connector bores for receiving electrical lead connectors used to couple to individual cardiac pacing and sensing electrodes.
Traditionally, incompatibility between the configuration of the connector block and the connector assemblies on the implanted leads has been addressed by means of adapters. Typically, these adapters take the form of a relatively short lead which at one end has a connector assembly which may be inserted into one or more bores on the connector block on the implantable device and at the other end has one or more connector bores capable of receiving the connector assembly or assemblies on the electrical leads to be used with the device. These adapters are bulky and add substantially to the size of the pocket in which the device is to be implanted. In addition, they tend to require a number of additional steps to be performed by the physician in order to couple the leads to the implanted device, and are thus seen as undesirable generally. Such adapters are disclosed in U.S. Pat. No. 5,000,177, issued to Hoffmann, and U.S. Pat. No. 5,328,442, issued to Levine. Some adapters, such as disclosed in U.S. Pat. Nos. 5,050,602 issued to Osypka and 5,060,649 issued to Hocherl et al. even required removal of the connector assembly of the lead as part of the connection process. Another approach to resolving lead/device incompatibility problems is the up-sizing sleeve, as disclosed in U.S. Pat. No. 4,583,543, issued to Peers-Trevarton and U.S. Pat. No. 5,007,864, issued to Stutz Jr. However, up-sizing sleeves are usable only in cases in which the connector assembly of the lead is smaller than the connector bore, and only in some of these cases. While it would be preferable if a universal interconnection system could be developed for use in conjunction with implantable pacemakers, cardioverters and defibrillators, this goal remains elusive.